The subject application relates generally to a header for use with agricultural harvesters. In particular, the subject application relates to an adjustable row unit deck plate for an agricultural harvester header.
The header of an agricultural harvester or combine is provided with row dividers and associated hoods for directing rows of corn stalks to downstream separation devices known as row units. The row units include stalk receiving slots or gaps and stripping plates, snapping rolls, and opposed rearwardly moving gathering chains. Thus, e.g., following separation of ears from stalks by the snapping rolls and stripping plates (also known as stalk rolls and deck plates, respectively), the separated ears are delivered by the gathering chains to an auger or other suitable conveyor which conveys the harvested ears to a feederhouse of the combine. Harvested ears are then processed to the combine's inner chambers for downstream processing.
Row unit frames are typically constructed with forwardly projecting members that support several components of the row unit including the deck plates, the stalk roll support bearings, the front gathering chain idlers, the hood and the row divider. As is known, the stalk rolls are disposed beneath the deck plates and are cooperatively rotated to pull the corn stalks downwardly into the stalk receiving slots where the ears come into contact with the deck plates and are snapped off of the stalks by the deck plates. The lateral spacing between deck plates is often achieved by a control linkage which connects at least one movable deck plate to an extensible actuator such as a hydraulic cylinder or the like. Extension and retraction of the actuator moves one or both of the deck plates in a direction transverse to the direction of travel of the header, e.g., a medial or lateral direction of the header, in order to adjust the gap or spacing between the deck plates to accommodate the crop being harvested.
A disadvantage of presently available headers is that individual deck plates do not maintain their parallelism as crop is being harvested. Despite the presence of the control linkage(s), individual deck plates often misalign with respect to the row unit during operation whereby either the fore or aft portions of the deck plate converge or diverge out of a substantially parallel alignment with an opposing deck plate. Under such circumstances, if the fore regions of the deck plates converge too severely, then the leading edges of the deck plates will prevent a portion of the crop from being harvested. Conversely, if the fore regions of the deck plates diverge too severely, then they may prevent certain ears of crop from being stripped from the stalk by the deck plates, whereby crop is left on the stalk as it is pulled under by the stalk rolls, thereby also reducing crop yield. Furthermore, if the fore regions of the deck plates are too divergent, then the aft end of the crop receiving gap will clog with stalk debris which requires periodic stoppage of the harvesting operation in order to remove the crop matter from between the deck plates.
Moreover, parallelism between deck plates is not always maintained when the control linkage is extended and retracted. That is, when the control linkage is retracted the deck plates may stray from essentially parallel relationship whereby the leading or fore edges of the deck plates often tend to converge or come together in a “toe-in” or snowplow arrangement. In such a position, the leading edges of the deck plates will prevent a portion of the crop from being harvested.
Further, when the control linkage is extended the deck plates may also stray from essentially parallel relationship in the opposite direction whereby the leading or fore edges of the deck plates tend to diverge or spread apart in a “toe-out” configuration. In such a position, the leading edges of the deck plates will prevent a portion of the crop from being harvested.